Kenmore 63654, 63652 Service Manual
DIVISION 22
BASIC FIELD MANUAL
FOR
MICROWAVE OVEN
MODEL 721.63652300 / 721.63652301
721.63659300 / 721.63659301
721.63654300 / 721.63654301
721.63653300 / 721.63653301
June, 2005
MODEL 721.63652
721.63659
721.63654
721.63653
CAUTION
SAFETY PRECAUTIONS
PRECAUTIONS TO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE EXPOSURE
TO EXCESSIVE MICROWAVE ENERGY
a. Do not operate or allow the oven to be operated with the door open.
b. Make the following safety checks on all ovens to be serviced before activating the
magnetron or other microwave source, and make repairs as necessary; (1) Interlock
operation, (2) proper door closing, (3) seal and sealing surfaces (arcing, wear, and
other damage), (4) damage to or loosening of hinges and latches, (5) evidence of
dropping or abuse.
c. Before turning on microwave power for any service test or inspection within the
microwave generating compartments, check the magnetron, wave guide or
transmission line, and cavity for proper alignment, integrity, and connections.
d. Any defective or misadjusted components in the interlock, monitor, door seal, and
microwave generation and transmission systems shall be repaired, replaced, or
adjusted by procedures described in this manual before the oven is released to the
owner.
e. A Microwave leakage check to verify compliance with the Fedenal Performance
Standard should be performed on each oven prior to release to the owner.
• Proper operation of the microwave ovens requires that the magnetron be assembled to the
wave guide and cavity. Never operate the magnetron unless it is properly installed.
• Be sure that the magnetron gasket is properly installed around the dome of the tube whenever
installing the magnetron.
• Routine service safety procedures should be exercised at all times.
• Untrained personnel should not attempt service without a thorough review of the test
procedures and safety information contained in this manual.
TABLE OF CONTENTS
(Page)
SAFETY PRECAUTIONS .............................................................................................................. Inside front page
SPECIFICATIONS ............................................................................................................................................... 1-1
CAUTIONS .......................................................................................................................................................... 2-1
INSTALLATIONS ................................................................................................................................................. 3-1
OPERATING INS ................................................................................................................................................. 4-1
CONTROL PANEL ....................................................................................................................................... 4-1
CONTROL PANEL INSTRUCTIONS ........................................................................................................... 4-2
OVERALL CIRCUIT DIAGRAM ........................................................................................................................... 5-1
SCHEMATIC DIAGRAM (I) .......................................................................................................................... 5-1
SCHEMATIC DIAGRAM (II) ......................................................................................................................... 5-2
MATRIX CIRCUIT FOR TOUCH KEY BOARD ............................................................................................ 5-3
GENERAL INFORMATION FOR SERVICE ........................................................................................................ 6-1
GENERAL PRECAUTIONS IN USE ............................................................................................................ 6-1
TRIAL OPERATION ..................................................................................................................................... 6-1
FEATURES AND SPECIFICATIONS FEATURES ...................................................................................... 6-1
SERVICE INFORMATION ................................................................................................................................... 7-1
PRECAUTIONS AND REPAIR SERVICE TIPS ........................................................................................... 7-1
MICROWAVE LEAKAGE TEST ................................................................................................................... 7-2
POWER OUTPUT MEASUREMENT ........................................................................................................... 7-3
DISASSEMBLY INSTRUCTIONS ................................................................................................................ 7-4
INTERLOCK SYSTEM ............................................................................................................................... 7-12
INTERLOCK CONTINUITY TEST .............................................................................................................. 7-14
TEST AND CHECKOUT PROCEDURES AND TROUBLE SHOOTING ................................................... 7-15
A. TEST PROCEDURES .................................................................................................................... 7-15
B. CHECKOUT PROCEDURES ......................................................................................................... 7-18
C. TROUBLE SHOOTING .................................................................................................................. 7-21
EXPLODED VIEW ............................................................................................................................................... 8-1
FOREWORD
Read this Manual carefully. Failure to adhere to or observe the information in this Manual may result in exposing
yourself to the Microwave Energy normally contained within the oven cavity.
MODEL 721. 63652
721. 63659
721. 63654
721. 63653
1-1
Rated Power Consumption..................................................1,500W maximum (Microwave oven+Cook top lamps+Ventilation fan)
Microwave Output.................................................................1000W (IEC 60705)
Adjustable 100W through 1000W, 10 steps
Frequency.............................................................................2,450 MHz 50 MHz
Power Supply........................................................................120 VAC, 60 Hz
Rated Current.......................................................................13 Amp. (Microwave oven+Cook top lamps+Ventilation fan)
Magnetron Cooling...............................................................Forced Air Cooling
Rectification...........................................................................Rectification Voltage Double Half-Wave
Door Sealing.........................................................................Choke System
Safety Devices...................................................................... Magnetron Thermal Fuse:
Open at 109°C 4°C
Oven Cavity Thermostat:
Open at 110°C 5°C
Fuse(20A)
Primary Interlock Switch
Secondary Interlock Switch
Interlock Monitor
Magnetron............................................................................. 2M248
High Voltage Capacitor........................................................Capacitor: 1.0µF, 2.1 KV AC
High Voltage Diode...............................................................Diode; 350mA, 9.0 KV
Cook top Lamp.....................................................................125 V, 30 W
Cavity Lamp..........................................................................125 V, 30 W
Timer.....................................................................................Digital, up to 99 mim. 99 sec. (in each cooking stage)
Tray .......................................................................................Tempered Safety Glass
Overall Dimensions..............................................................29
15
/16”(W)x167/16”(D)x155/8”(H)
Oven Cavity Size .................................................................22
3
/8”(W)x10”(D)x1419/32”(H)
Effective Capacity of Oven Cavity.......................................1.8 Cu.ft.
Accessories...........................................................................Owner’s Manual & Cooking Guide, Installation Manual,
Exhaust Adapter, Exhaust Damper, Mounting Kit and Two Filters,
Rotating Ring Assembly, Metal Rack, Defrosting Plate.
SPECIFICATIONS
2-1
CAUTIONS
• DO NOT operate on a 2-wire extension cord during
repair and use.
• NEVER TOUCH any oven components or wiring during
operation.
• BEFORE TOUCHING any parts of the oven, always
remove the power plug from the outlet.
• For about 30 seconds after the oven stops, an electric
charge remains in the high voltage capacitor. When
replacing or checking, you must discharge the high
voltage capacitor by shorting across the two terminals
with an insulated screwdriver.
•
Remove your watch whenever working close to or
replacing the Magnetron.
• DO NOT touch any parts of the control panel circuit. A
resulting static electric discharge may damage this
P.C.B.
• NEVER operate the oven with no load.
• NEVER injure the door seal and front plate of the oven
cavity.
• NEVER put iron tools on the magnetron.
• NEVER put anything into the latch hole and the interlock
switches area.
• Proper operation of the microwave oven requires that
the magnetron be assembled to the waveguide and
cavity. Never operate the magnetron unless it is
properly installed.
• Be sure that the magnetron gasket is properly
installed around the dome of the tube whenever
installing the magnetron.
Unlike other appliances, the microwave oven is
high-voltage and high-current equipment.
Though it is free from danger in ordinary use,
extreme care should be taken during repair.
THE OVEN IS TO BE SERVICED ONLY
BY PROPERLY QUALIFIED SERVICE
PERSONNEL.
MICROWAVE RADIATION
Personnel should not be exposed to the
microwave energy which may radiate from the
magnetron or other microwave generating
device if it is improperly used or connection.
All input and output microwave connections,
waveguide, flange, and gasket must be secure.
Never operate the device without a microwave
energy absorbing load attached.
Never look into an open waveguide or antenna
while the device is energized.
Gasket
ANTENNA
COOLING FIN
MAGNETRON
CHASSIS GROUND
FILAMENT
TERMINALS
MAGNETRON
3-1
INSTALLATION
PRECAUTIONS ON INSTALLATION
A. Plug the power supply cord into a 120V AC, 60Hz,
single-phase power source with a capacity of 15A
or 20A.
B. Avoid placing the unit in a location where there is
direct heat or splashing water.
C. Install the unit on the mounting plate firmly.
D. Place the unit as far away as possible from TV,
radio, etc. to prevent interference.
GROUNDING INSTRUCTIONS
For personal safety, this appliance must be fully
grounded at all times.
In the event of an electrical short circuit, grounding
reduces the risk of electrical shock.
The plug must be plugged into an outlet that is
properly installed and grounded.
BEFORE YOU BEGIN, READ THE FOLLOWING INSTRUCTIONS COMPLETELY AND CAREFULLY.
WARNING
Improper use of the grounding plug can result in a
risk of electric shock.
Do not, under any circumstances, cut or remove the
third ground prong from the power cord plug.
CAUTION
This unit is equipped with a 3-prong plug for your
safety. If the wall outlet is a grounded 3-hole type,
the unit will be grounded automatically.
Plug with Ground
Prong
Properly Polarized
and Grounded
Outlet
CONTROL PANEL
4-1
OPERATING INSTRUCTIONS
1
2
5
8
11
14
17
18
20
23
26
29
4
7
10
13
16
19
22
25
28
31
12
24
30
6
3
9
15
21
27
CONTROL PANEL INSTRUCTIONS
4-2
1. Display. The display includes a clock and indicators to
tell you time of day, cooking time settings, cook
powers, quantities, weights and cooking functions
selected.
2. Dinner Plate. Touch this pad to cook without entering
a cook time or power.
3. Frozen Entree. Touch this pad to cook a 10 - to 20 -
ounce (284 to 567 g) frozen entree without entering a
cook time or power.
4. Soup or Sauce. Touch this pad to cook without
entering a cook time or power.
5. Frozen Vegetable. Touch this pad to cook without
entering a cook time or power.
6. Fresh Vegetable. Touch this pad to cook without
entering a cook time or power.
7. Canned Vegetable. Touch this pad to cook without
entering a cook time or power.
8. Popcorn. Touch this pad to pop popcorn with the
sensor feature. The oven’s sensor will tell the oven
how long to cook depending on the amount of
humidity it detects from the popcorn.
9. Pizza. Touch this pad to reheat one or several slices
of pizza without entering a cook time or power.
10. Potato. Touch this pad to cook potatoes without
entering a cook time or power.
11. Auto Defrost. Touch this pad followed by Number
Pads to thaw frozen meat by weight.
12. Express Defrost. Touch this pad to express defrost.
“GROUND BEEF 1.0 LBS TOUCH START” will
appear in the display.
13. Favorite Recipe. Touch this pad to recall one
cooking instruction previously programmed into
memory.
14. Auto Cook. Touch this pad to cook microwavable
foods without entering a cook time or power.
15. Auto Reheat. Touch this pad to reheat
microwavable foods without entering a cook time or
power.
16. Hold Warm. Touch this pad to keep hot, cooked
foods safely warm in your oven for up to 99 minutes,
99 seconds. Hold Warm can be used by itself, or it
can automatically follow a cooking cycle.
17. Number Pads. Touch number pads to enter cooking
times, cook powers, quantities, weights, or food
categories.
18. Cook Time. Touch this pad followed by Number
Pads to set a cooking time.
19. Power. Touch this pad after the cook time has been
set, followed by a Number Pad to set the amount of
microwave energy released to cook the food. The
higher the number, the higher the microwave power
or “cooking speed.”
20. More. Touch this pad to add 10 seconds of cook
time each time you press it.
21. Less. Touch this pad to subtract 10 seconds of cook
time each time you press it.
22. Option. Touch this pad to change the oven’s default
settings for sound, clock, display speed and defrost
weight.
23. Turntable On/Off. Touch this pad to turn off the
turntable. “T/TABLE OFF” will appear in the display.
24. Clock. Touch this pad to enter the correct time of
day.
25. Kitchen Timer. Touch this pad to set the kitchen
timer.
26. Add Minute. Touch this pad to cook for 1 minute at
100% cook power, or to add extra minutes at the set
cook power to your cooking cycle.
27. START. Touch this pad to start a function. If you
open the door after the oven begins to cook, retouch
START.
28. STOP/Clear. Touch this pad to erase an incorrect
command, cancel a program during cooking, or to
clear the Display.
29. Fan ( ) On/Off. Touch this pad to turn the fan on
or off.
30. Fan ( ) 5 Speed. Touch this pad to choose one of
5 fan speeds.
31. Light ( ). Touch this pad to turn the light on high,
night or off.
NOTE: If you try to enter incorrect instructions, you will
not hear any tones. Touch STOP/Clear and re-enter the
instructions.
5-1
OVERALL CIRCUIT DIAGRAM
SCHEMATIC DIAGRAM (I) *Check the Model No.
5-2
SCHEMATIC DIAGRAM (II) *Check the Model No. (ADD Noise filter)
5-3
MATRIX CIRCUIT FOR TOUCH KEY BOARD
Warm
Dinner
Plate
START
Kitchen
Timer
Auto
Defrost
Option
N.C
Power
Time
Cook
Cook
STOP
Clear
VENT
On/Off
Frozen
Vegetable
Vegetable
Fresh
Auto
Reheat
Auto
VENT
5 Speed
Frozen
Entree
Potato
High/Night/Off
LIGHT
Favorite
Recipe
Hold
1
2
3
4
Less
Clock
More
8
9
0
Canned
Vegetable
Pizza
Add
Minute
Defrost
Express
Sauce
Soup or
Popcorn
Turntable
N.C N.C
On/Off
5
6
7
13
12
11
10
9
8
2
1
3
7
4
5
6
6-1
GENERAL PRECAUTIONS IN USE
A. Never operate the unit when it is empty.
Operating the oven with no load may shorten the
life of the magnetron. Whenever cooking dry foods
(dried fish, bread, etc.) or a small amount of food,
be sure to put a glass of water into the cooking
compartment. The glass turntable may become hot
after operating, be careful when touching it.
B. Aluminum foil should be avoided because it will
disrupt cooking and may cause arcing. However,
small pieces may be used to cover some parts of
food to slow the cooking. Any aluminum foil used
should never be closer than 2.5 cm to any side wall
of the oven.
TRIAL OPERATION
After installation, the following sequences and results
should be checked carefully.
A. Put a container filled with water (about 1 liter) into
the oven, and close the door tightly.
B. Set cooking time for 10 minutes by touching “1”
and then “0” three times. “1, 0, 0, 0” appears in
the display window.
C. Touch the START key.
Make sure the cavity light comes on. The unit will
begin cooking and the display window will show the
time counting down by seconds.
D. After about 5 minutes, make sure the primary
interlock switch, the secondary interlock switch and
the interlock monitor switch operate properly by
opening and closing the door several times. Touch
the START key each time the door is closed.
E. Continue operating the unit. Four long beep sound
signal is heard when the time is up. The unit will
shut off automatically.
F. Confirm the water is hot.
G. Finally, measure the output power according to
“POWER OUTPUT MEASUREMENT” on
page 7-3.
FEATURES AND SPECIFICATIONS
FEATURES
A. The safety systems incorporated in this model are:
(1) Primary interlock switch
(2) Secondary interlock switch
(3) Interlock monitor switch
(4) Choke system
(5) Magnetron thermal fuse
(6) Oven cavity thermostat
(Note: This thermostat located on the oven
cavity will open and stop the unit from operation
only if a high temperature is reached, such as,
a fire created by overcooking food.)
B. Any one of 10 power output levels ranging 100W to
1000W can be selected by the touch control and
electronic computer system.
GENERAL INFORMATION FOR SERVICE
PRELIMINARY
A. SINCE NEARLY 2,100 VOLTS EXISTS IN SOME
CIRCUITS OF THIS UNIT REPAIRS SHOULD BE
CARRIED OUT WITH GREAT CARE.
The filament leads of magnetron carry High
Voltage with respect to ground. Extreme caution
must be exercised. Never plug the unit into a
power source to determine which component is
defective in high voltage section.
B. TO AVOID POSSIBLE EXPOSURE TO
MICROWAVE ENERGY LEAKAGE, THE
FOLLOWING PRECAUTIONS MUST BE TAKEN
BEFORE SERVICING.
(1) Before the power is applied:
(a) Make sure the primary interlock switch, the
secondary interlock switch and the interlock
monitor switch operate properly by opening
and closing the door several by opening and
closing the door several times.
(b) Make sure the perforated screen and the
dielectric choke of the door are correctly and
firmly mounted.
(2) After power is applied:
(a) Make sure the interlock switch mechanism
is operating properly by opening and closing
the door.
(b) Check microwave energy leakage must bebelow
the limit of 5 mW/cm
2
.
(All service adjustments should be made for
minimum microwave energy leakage
readings).
(3) Do not operate the unit until it is completely
repaired, if any of the following conditions exist.
The unit must not be operated.
(a) The door does not close firmly.
(b) The hinge is broken.
(c) The door seal is damaged.
(d) The door is bent or warped, or there is any
other visible damage on the unit that may
cause microwave energy leakage.
NOTE: Always keep the seal clean.
(e) Make sure that there are no defective parts
in the interlock mechanism.
(f) Make sure that there are no detective parts
in the microwave generating and transmission
assembly (especially waveguide).
(4) The following items should be checked after the
unit is repaired:
(a) The interlock monitor switch is connected
correctly and firmly.
(b) The magnetron gasket is properly positioned
and mounted.
(c) The waveguide and the oven cavity are intact.
(no microwave energy leakage)
(d) The door can be properly closed and the
safety switches work properly.
(e) The unit must stop when the door is opened or
the time is up.
The unit must not be operated with any of the above
components removed or by-passed.
7-1
PRECAUTIONS AND REPAIR SERVICE TIPS
SERVICE INFORMATION
7-2
CAUTIONS
• Be sure to check microwave leakage prior to
servicing the oven if the oven is operative prior to
servicing.
• The service personnel should inform the
manufacture importer, or assembler of any certified
oven unit found to have a microwave emission level
in excess of 5 mW/cm2and should repair any unit
found to have excessive emission levels, at no cost to
the owner, and should ascertain the cause of the
excessive leakage. The service personnel should
instruct the owner not to use the unit until the oven has
been brought into compliance.
• If the oven operates with the door open, the service
personnel should:
- Tell the user not to operate the oven.
- Contact the manufacturer and CDRH
(Center for Devices and Radiological Health)
immediately.
NOTE: Address on CDRH
Office of Compliance(HFZ-312)
Center for Devices and Radiological
Healthe 1390, Piccard Drive,
Rockville. MD 20850
• The service personnel should check all surface and
vent openings for microwave leakage.
• Check for microwave leakage after every servicing. The
power density of the microwave radiation leakage
emitted by the microwave oven should not exceed
4 mW/cm2. Always start measuring of an unknown field
to assure safety for operating personnel from radiation
leakage.
EQUIPMENT
• TESTER (VOLTS-DC, AC, Ohmmeter)
• Microwave survey meter
- Holaday HI-1500
HI-1501
- Narda 8100
8200
• 600 cc non conductive material beaker (glass or
plastic), inside diameter: approx. 8.5 cm (3
1
/2 in.)
• Glass thermometer: 100°C or 212°F (1 deg scale)
MEASURING MICROWAVE ENERGY
LEAKAGE
• Pour 275±15cc of 20±5°C(68±9°F) water in a beaker
which is graduated to 600 cc, and place the beaker
on the center of the turntable.
• Set the energy leakage monitor to 2,450 MHz and
use it following the manufacturer's recommended
test procedure to assure correct result.
• When measuring the leakage, always use the 2-inch
(5cm) spacer supplied with the probe.
• Operate the oven at its maximum output.
• Measure the microwave radiation using an
electromagnetic radiation monitor by holding the
probe perpendicular to the surface being measured.
Move probe along shaded area.
Probe scanning speed
Less than 2.5 cm/sec. ( 1 in/sec)
MICROWAVE LEAKAGE TEST
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